The overall goal of this proposal is to conduct ecological and biochemical studies on the cultivable oral treponemes which are found in the periodontal disease-associated human dental plaques. These studies will be focused on the following organisms: T. denticola, T. vincentii, T. socranskii subspecies socranskii, paredis, buccalis and an unnamed new Treponema sp isolated in this laboratory. Since these organisms are among the suspected periodontal pathogens and very little is known about them regarding their ecology, biochemical and physiological activities, a through investigation of this type is highly warranted. During the tenure of this project the prevalence of these organisms in the dental plaques of individuals with and without gingivitis and periodontal disease, will be assessed using fluorescent antibody and cultural techniques. Representative isolates from the plaques will be purified and identified on the basis of conventional physiological tests, immunofluorescence test, enzyme profiles using a rapid test system, as well as cellular protein pattern analysis by SDS-PAGE. American Type Culture Collection (ATCC) reference strains will be utilized as controls. At least 10 to 12 strains of each species or subspecies will be isolated from the plaques, well characterized and preserved by freezing in liquid nitrogen and/or by lyophilization for biochemical studies which will focus on purification of selected collagenlytic proteinases and their characterization. This will be carried out by gel permeation, ion exchange and other separation techniques, using parmarily a high-performance biocompatible fast protein liquid chromatograpy system (FPLC). Preliminary studies on T. denticola have shown that this organism grows in the restricted aerobic environment in test tubes containing unreduced broth media and survives for several hours in the room atmosphere. Attempts will be made to grow this organism in different concentrations of molecular oxygen in the growth environment and to examine the effect of oxygen on the microscopic morphology, motility, superoxide dismutase production and cellular protein synthesis by this organism. Since other species are more fastidious and grow slowly even under continuous anaerobic conditions, these studies will be restricted to T. denticola. However, all species will be tested for superoxide dismutase activity. The overall information obtained from these studies could be used as a basis for future investigations dealing with pathogenic mechanisms and etiologic role of spirochetes i periodontal infections. The research facilities of the laboratories are excellent for the research work proposed in this application